09a2c73ddf ("PCI: Remove unused PCI_MSIX_FLAGS_BIRMASK definition")
removed PCI_MSIX_FLAGS_BIRMASK from an exported header because it was
unused in the kernel. But that breaks user programs that were using it
(QEMU in particular).
Restore the PCI_MSIX_FLAGS_BIRMASK definition.
[bhelgaas: changelog]
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v3.13+